Conventionally, there exists an antenna device that includes a first antenna that is a chip-type antenna for operating in a GSM band, a second antenna that is a pattern antenna for operating in DCS and PCS bands, and a third antenna that is a stacked antenna for operating in an UMTS band. The antennas are provided on a substrate. The second antenna is provided via a line extending from a power feeding port connected to the first antenna. A gap G is interposed between the second antenna and the third antenna on the substrate such that the second antenna is capacitively coupled to the third antenna without providing an antenna switch (see Patent Document 1, for example).
Here, in the above antenna apparatus, the second antenna is capacitively coupled to the third antenna for impedance matching but is not provided to improve efficiency (radiation efficiency, in particular) of the antenna apparatus.